The present application relates generally to an improved data processing apparatus and method and more specifically to an apparatus and method for reducing storage system power consumption in a remote copy configuration.
Many large business entities enter into power usage agreements that cap power utilization for a facility. The power utilization cap may vary during different time periods. The financial penalty for violating the power utilization cap can be very high.
For disk storage systems, power consumption is a function of the number of active drives and input/output (I/O) activity at the drives. For large disk arrays, the power requirements are dominated by the disk drive power needs. Reduction of power consumption may be accomplished by turning off drives or by reducing host I/O demand.
In practice, turning off drives or reducing I/O demand may be impractical. Performance requirements on the system may not tolerate the long access time required to turn on a drive to access the data. Also, the business needs may not permit reduction of I/O demand.